At least 12 people were killed when Cyclone Gonu struck the Gulf country of Oman, an emergency official said Thursday. The storm was the strongest to hit the Gulf for decades, damaging buildings and trees in Oman's capital, Muscat, and leaving many roads flooded.

High winds and heavy rain were also reported, and electricity and water supplies were interrupted.

Abdullah al-Harthi, a spokesman for the Royal Oman Police, told local TV at least 12 people had died in the cyclone.

The storm headed from Oman to the southeastern Iranian coast, but continued to lose steam, dropping off to tropical storm strength early Thursday, according to the U.S. military's Joint Typhoon Warning Center.

Residents along the coast of southern Iran have moved to higher ground and sought shelter in schools and mosques.

The Iranian town of Jask has reported high winds, heavy rain and overflowing rivers.